Microsoft is testing a weird change to the Bing Search results user experience. Bing is testing that when you do a search from the home page, that it opens the search results in a new window, instead of loading those results on the same tab you are on. Bing is also testing opening a new window for when you click to the next page of the search results.
I personally can see Bing testing opening the results in a new window from the home page search box. It happened for me in Chrome but I was not able to replicate in Safari.
Here is a GIF of it in action:
Frank Sandtmann posted on Mastodon where Bing Search is testing opening a new window when you click on the next set of results from the pagination bar.
He posted this screenshot of this:
I cannot replicate the pagination bar functionality but I can the home page.
Bing had a toggle to open results in a new window after you click on a search result but to open the search result listings page in a new window is super weird.
